
/* @(#)w_scalb.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

/*
 * wrapper scalb(double x, double fn) is provide for
 * passing various standard test suite. One
 * should use scalbn() instead.
 */

#include "fdlibm.h"
#include <errno.h>

#ifndef _DOUBLE_IS_32BITS

#ifdef __STDC__
#ifdef _SCALB_INT
    double scalb(double x, int fn)      /* wrapper scalb */
#else
    double scalb(double x, double fn)   /* wrapper scalb */
#endif
#else
    double scalb(x,fn)          /* wrapper scalb */
#ifdef _SCALB_INT
    double x; int fn;
#else
    double x,fn;
#endif
#endif
{
#ifdef _IEEE_LIBM
    return __ieee754_scalb(x,fn);
#else
    double z;
#ifndef HUGE_VAL
#define HUGE_VAL inf
    double inf = 0.0;

    SET_HIGH_WORD(inf,0x7ff00000);  /* set inf to infinite */
#endif
    struct exception exc;
    z = __ieee754_scalb(x,fn);
    if(_LIB_VERSION == _IEEE_) return z;
    if(!(finite(z)||isnan(z))&&finite(x)) {
        /* scalb overflow; SVID also returns +-HUGE_VAL */
        exc.type = OVERFLOW;
        exc.name = "scalb";
        exc.err = 0;
        exc.arg1 = x;
        exc.arg2 = fn;
        exc.retval = x > 0.0 ? HUGE_VAL : -HUGE_VAL;
        if (_LIB_VERSION == _POSIX_)
           Djy_SaveLastError(ERANGE);
        else if (!matherr(&exc)) {
           Djy_SaveLastError(ERANGE);
        }
        if (exc.err != 0)
           Djy_SaveLastError(exc.err);
            return exc.retval;
    }
    if(z==0.0&&z!=x) {
        /* scalb underflow */
        exc.type = UNDERFLOW;
        exc.name = "scalb";
        exc.err = 0;
        exc.arg1 = x;
        exc.arg2 = fn;
        exc.retval = copysign(0.0,x);
        if (_LIB_VERSION == _POSIX_)
           Djy_SaveLastError(ERANGE);
        else if (!matherr(&exc)) {
           Djy_SaveLastError(ERANGE);
        }
        if (exc.err != 0)
           Djy_SaveLastError(exc.err);
            return exc.retval;
    }
#ifndef _SCALB_INT
    if(!finite(fn)) Djy_SaveLastError(ERANGE);
#endif
    return z;
#endif
}

#endif /* defined(_DOUBLE_IS_32BITS) */
